Rorate Caeli

Allelúia, Christum Dóminum ascendéntem in cælum, Veníte adorémus, allelúia.

Ye men of Galilee, why stand you looking up to heaven? alleluia: This Jesus who is taken up from you into heaven, shall so come, as you have seen him going into heaven, alleluia, alleuia, alleluia. (Acts 1, 11)

 (Ascension of Our Lord into Heaven depicted by John Singleton Copley 1775. Source: Wiki)